Mojo JS bindings: remove the connection module.

mojo/public/js/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 source_set("js") {
   sources = [
     "constants.cc",
     "constants.h",
   ]
 }
 
 group("bindings") {
   data = [
     "bindings.js",
     "buffer.js",
     "codec.js",
-    "connection.js",
     "connector.js",
     "constants.cc",
     "constants.h",
     "core.js",
     "interface_types.js",
     "router.js",
     "support.js",
     "threading.js",
     "unicode.js",
     "validator.js",
   ]
 }
 
 group("tests") {
   testonly = true
 
   data = [
     "codec_unittests.js",
     "core_unittests.js",
     "struct_unittests.js",
     "test/validation_test_input_parser.js",
     "union_unittests.js",
     "validation_unittests.js",
     "//mojo/public/interfaces/bindings/tests/data/validation/",
   ]
   public_deps = [
     ":bindings",
   ]
 }